The U.S. wind power industry spent $25 billion adding capacity in 2012, a year that also saw Texas extend its lead as the biggest generator of electricity from wind.Developers installed 13,131 megawatts of wind capacity nationwide, including 1,826 megawatts in Texas, the most among the states, according to a report by the American Wind Energy Association. The additions gave Texas 12,214 megawatts of capacity -- more than total U.S. wind capacity of about 10,000 megawatts in 2006.A megawatt is 1 million watts. That's roughly enough to keep the lights on and the air conditioners humming at about 200 typical Texas residences on a really hot summer day, or 500 homes during average temperatures.California, Kansas, Oklahoma, Illinois and Iowa trailed Texas in wind capacity additions. Fifteen states now have at least 1,000 megawatts of capacity.Texas has six of the nation's largest wind farms, but the Shepherd's Flat farm in Oregon is the largest project in the country, with 845 megawatts of capacity. Texas' largest installation is the Roscoe wind farm, operated by E.ON Climate & Renewables, about 50 miles west of Abilene.Wind accounted for 5.6 percent of U.S. electricity-generating capacity in 2012, up from about 3 percent in 2011.Texas, the biggest electricity market in the country, got 7.4 percent of its total demand from wind last year. That's lower than wind's 9.2 percent share of power used last year in the Electric Reliability Council of Texas, which covers 75 percent of the state but includes most of the state's wind installations.The wind association estimated Texas' wind-related jobs at more than 10,000, the highest in the nation.